In terms of mechanical structure, the core influencing factors include three points: first, the drop height control mechanism. Screw pitch error and chain slippage can cause height deviation, and loose installation of height sensors can amplify errors. The impact energy is positively correlated with height and directly affects the test results; The second is the specimen release mechanism. Uneven electromagnetic attraction or mechanical buckle rebound can cause the specimen to deviate from the free fall state, and the support platform to warp and change the landing posture (such as surface drop becoming angular drop); The third issue is falling from the floor and frame. Insufficient rigidity of the floor (such as steel plate thickness<10mm) can absorb impact energy, while vertical deviation of the frame (>0.5mm/m) can cause the fall trajectory to tilt.

The control and measurement system is the key to accurate data. Control system response delay (>10ms) can cause height deviation, especially in high-speed lifting scenarios; Insufficient resolution of the height encoder (such as<1000 lines) and irregular calibration of the acceleration sensor (more than 6 months) can result in an error of over 5% between the height and impact data; If the sampling rate is too low (<10kHz), it will also miss the impulse peak and cause data distortion.

The interference of environmental conditions cannot be ignored. Temperatures below 0 ℃ will cause lubrication failure of mechanical components, while temperatures above 40 ℃ will reduce sensor sensitivity; Humidity exceeding 85% RH can easily cause electrical components to become damp; Environmental vibration greater than 0.5g or ground level error greater than 1 ° will cause the frame to shake, the specimen to deviate, and damage the stability of the drop.

The characteristics of the specimen can also affect accuracy. Weight exceeding the rated load of the equipment will cause overload of the lifting system, while being too light (<1kg) will be greatly affected by air resistance; The deviation of the center of gravity or asymmetric structure will cause the specimen to flip and change its landing posture; Flexible packaging is prone to friction with the platform, deviating from the free fall state, resulting in poor data repeatability.